Question

Решить уравнение: cos (x-p/4) = -1/2

Answer 1

cos(x - π/4) = -1/2
x - π/4 = ±2π/3 + 2πn, n ∈ Z
x = ±2π/3  + π/4 + 2πn, n ∈ Z
Ответ: x = ±2π/3  + π/4 + 2πn, n ∈ Z.

P.s.: arccos(-x) = π - arccosx